Method of producing hydrometer floats



May 15, 1934. H. E. CHRISTIE ET AL METHOD OF PRODUCING HYDROMETER FLOATSFiled Jan. 6, 1930 m si e MW Ti a AW? m m V W m Wm A a w Patented May15, 1934 Y NITED STATES PATENT OFFICE METHOD OF PRODUCING HYDROMETERFLOATS Application January 6, 1930, Serial No. 418,736

11 Claims.

This invention relates to an improvement in method of producinghydrometer floats, and particularly to a method by which to producemetallic hydromoter floats.

An object of the invention is to provide a simple and practical methodaccording to which hydromoter floats made of metal may be quickly andeasily produced at small cost.

A further object is to provide a method by which any number ofhydrometer floats may be produced with great accuracy.

A further object is to provide a method by which to produce hydrometerfloats and by which the weight of each individual float may be quicldy,easily and accurately altered so that the float will stand at apredetermined level in use.

A further object is to provide a new and improved method by which to addweight to a hydrometer float.

A further object is to provide a new and improved method by whichhydrometer floats of any desired contour may be readily and cheaplyproduced.

Other objects and aims of the invention, more or less specific thanthose referred to above, will be in part obvious and in part pointed outin the course of the following description of the elements,combinations, arrangements of parts and applications of principlesconstituting the invention; and the scope of protection contemplatedWill be indicated in the appended claims.

In the accompanying drawing which is to be taken as a part of thisspecification, and in which I have shown merely a preferred form ofembodiment of the invention:

Fig. 1 is a side elevational view of a core piece used in connectionwith this invention.

Figs. 2 and 3 are similar views showing progressive steps in theproduction of the float shell.

Fig. 4 is a detail sectional view illustrating the step by which weightis added to the float.

Fig. 5 is a sectional view illustrating the manner in which weight maybe removed, and

Fig. 6 illustrates a step which may or may not be used at the will ofthe operator.

In carrying out this method the first step is to provide a core piecehaving practically the size and proportions desired for the completedfloat. An example of such a core piece as L is illustrated in thedrawing Fig. l, the core piece in the present instance having been madefrom a metallic composition having a low melting point.

Having provided the core piece the operator places it in a suitableelectro-plating bath as 1 and in a well understood manner thus plates orcoats the entire exterior surface of the core with a desired thicknessof jacket or shell as G as illustrated in Fig. 2, the metal depositedupon the core having a relatively higher melting point than the metal ofthe core, being for instance preferably copper.

After a desired thickness of shell has been deposited then the whole isremoved from the bath and subjected to heat as illustrated in Fig. 3,the heat being at a predetermined and suflicient temperature to melt thecore L without injury to the material of the shell.

Just prior to subjecting the article to heat two small holes or openingsas 2 and 3 are drilled one i into the upper end and the other into thelower end, these holes extending through the material of the shell sothat air may enter through one thereof as that indicated 2 and so thatthe molten metal of the core may flow out through the other, as 3, asindicated by the arrow in Fig. 3.

It is to be observed that by this procedure the shell which remainsafter the heat treatment is actually of two thicknesses, an outerthickness as 4 of metal, such as copper deposited by electroplating, andan inner thickness as 5 of the metal from which the core was made, theinner thickness appearing as a tinning throughout the entire innersurface of the shell and serving thereby to re-inforce and toughen thecopper shell, as will be readily understood and as clearly indicated inthe drawing Fig. 4.

It is desirable that the lower end of the float should be weighted, andin order to provide this the present method proposes that the necessaryweight be introduced into the interior of the shell as molten metal andthereafter cooled. To this end the present invention contemplates theprovision of a container as H adapted to contain a quantity of moltenmetal as 6 preferably in the amount which it is desired shall beintroduced into the float. A heater as 7 may be provided to maintain themetal 6 in molten condition. The container, with its metal 6, havingbeen provided, the operator places the lower end of the float into themetal 6, as indicated in Fig. 4, and by sucking with his mouth, orotherwise, upon the upper end of the float, through opening 2, draws themetal 6 into the float through opening'3, as indicated by the dottedline 8, it being important to note in this connection that the tinningas 5 within the float at this time provides a proper surface with whichthe molten metal 6 engages and with which said metal readily bonds orfuses the heat of the metal 6 serving to melt so much of the tinning asit comes in contact with and thus causing the two to become fusedtogether when they have cooled.

When the float has been removed and allowed to again cool its lower endportion consists of a substantially solid body of metal consisting ofthe metallic weight piece 9 and the surrounding shell of the float, andit is proposed as a further step of the present method that wherevernecessary a desired portion of this solid metal may be removed, bycutting, grinding or otherwise. In Fig. 5, the portion indicated bydotted lines 1%) illustrates the part which has been removed so that theremainder shall comprise just the necessary amount of weight to causethe float to stand at a predetermined level in the liquid medium inwhich it is designed for use.

The weight piece 9 serves to seal the lower end of the shell, and it isintended that the opening 2 at the upper end may be sealed in anyappropriate manner, as for instance by the placing of a spec of cement,or solder, therein.

The exterior surface of the float may now be polished or otherwisefinished as may be desired, for instance it may be plated with a thincoating of gold or silver if desired.

It is further proposed by the present invention that if it be desired tore-inforce any portion of the float this may be accomplished by platingthat particular portion or portions of the core L before or otherproceeding to plate the entire core as above suggested with regard toFig. 2. Such a step is illustrated for instance in the drawing Fig. 6wherein it will be understood that the shaded parts of the core areplated with a suitable thickness of re-inforcing metal as 11 preparatoryto introducing the core into the bath 1.

It will of course be understood that the metal 11 has been deposited byelectro-plating the same as described with reference to Fig. 2 but thatduring the time while the metal 11 was being deposited all portions ofthe core upon which it is desired the metal 11 shall not occur areprotected by a suitable grease or other coating in a well understoodmanner.

By practicing the method herein illustrated and described it is madepossible toproduce any number of hydrometer floats all substantiallyidentical with each other, the degree of accuracy being such that scaleindications as 12-12 may be formed directly in the material of the upperor stem portion of the float, the addition or removal of weight at thebottom end of the float as above described serving as means by which tocorrect any slight variation in the weights of different floats so thatall may be made to stand at a given level in use. In order to providesuch scale indications it is intended that the core L, which is itselfof course cast in a suitable standard mold prepared for the purpose, beformed with suitable depressions therein shaped to correspond with scalelines and figures as indicated in Fig. 1 so that these depressions willbe reproduced in the metallic shell which is plated over the core, asindicated in Figs. 2 and 3, it being proposed as a further step of thepresent method that these depressions may be filled with suitablecoloring material, such as wax, paint or the like so they will beprominently visible to an observer.

It is also possible by this method to produce floats having shapedcharacteristics which would not be possible from a practical View pointin the manufacture of glass hydrometer floats.

Whie it is above set forth that the metal shell 4 is deposited byelectrical process it will of course be understood that this metal mayif desired be deposited by any other process such for instance as theschoop metal spraying process. It is also intended that if desired thecore piece illustrated in Fig. 1 may if preferred be made of materialother than metal, as for instance a waxy material, the essentialcharacteristic being simply that it will provide a readily meltable bodyor core of appropriate firmness and shape to receive the deposited metalthereon. Obviously where other than metal is used for this core howeverthe shell resulting after removal of the readily meltable core, platingsaid core to form u a thin metallic shell thereon, the core being ofmaterial having a relatively lower melting point than the metal of theshell, forming an opening through the shell, heating the whole to reducethe core material to a consistency for removal through said opening andremoving a portion of the core material through said opening but leavinga sufficient portion adhering to the inner surface of the shell toconstitute a thin lining upon the shell walls, and then adding a weight,7

within the shell at the lower end thereof.

2. The herein described method of producing hydrorneter floats, whichmethod consists in providing a readily meltable core, plating said coreto form a thin metallic shell thereon, the core 7 being of materialhaving a relatively lower melting point than the metal of the shell,forming an opening through the shell, heating the whole to reduce thecore material to a consistency for removal through said opening andremoving a portion of the core material through said opening but leavingthe remaining portion adhering to the inner surface of the shell, andthen attaching a weight to a remaining portion of said core material atthe lower end of the shell.

3. The herein described method of producing hydrometer floats, whichconsists in providing a readily meltable core, plating said core to forma thin metallic shell thereon, the core being of material having arelatively lower melting point than the metal of the shell, forming anopening through the shell, heating the whole to reduce the core materialto a consistencyfor removal through said opening and removing a portionof the core material through said opening but leaving the remainingportion adhering to the inner surface of the shell, attaching a metallicweight in molten form to the lower end of the shell in fused relation toa remaining portion of said core material, and then causing the moltenmaterial of said weight to solidify.

4. The herein described method of producing hydroineter floats, whichconsists in providing a readily meltable core, plating said core to forma thin metallic shell thereon, the core being of material having arelatively lower melting point than the metal of the shell, forming anopening through the shell, heating the whole to reduce the core materialto a consistency for removal of the but leaving the remaining portionadhering to the inner surface of the shell, attaching a metallic weightin molten form to the lower end of the shell in fused relation to aremaining portion of said core material causing the molten material ofthe weight to solidify, and then removing a portion of said weight andof said shell and of said remaining core material.

5. The herein described method of producing hydrometer floats, whichconsists in providing a readily meltable core, plating said core to forma thin metallic shell thereon, the core being of material having arelatively lower melting point than the metal of the shell, forming anopening through the shell, heating the whole to reduce the core materialto a consistency for removal through said opening and removing a portionof the core material through said opening but leaving the remainingportion adhering to the inner surface of the shell, and then causing aquantity of weight forming material to be drawn through said openinginto the shell sumcient to constitute a desired weight at the lower endof the shell.

6. The herein described method of producing hydrometer floats, whichconsists in providing a readily meltable core, plating said core to forma thin metallic shell thereon, the core being of material having arelatively lower melting point than the metal of the shell, forming anopening through the shell, heating the whole to reduce the core materialto a consistency for removal through said opening and removing a portionof the core material through said opening but leaving the remainingportion adhering to the inner surface of the shell, introducing throughsaid opening a quantity of molten metal into contact with a remainingportion of said core material at the lower end of the shell so as tobecome fused with said core material, and then causing said moltenmaterial to solidify.

'7. The herein described method of producing hydrometer floats, whichconsists in providing a readily meltable core, plating said core to forma thin metallic shell thereon, the core being of material having arelatively lower melting point than the metal of the shell, forming apair of openings through the shell, heating the whole to reduce the corematerial to a consistency for removal through said opening and removinga portion of the core material through said opening but leaving theremaining portion adhering to the inner surface of the shell, applyingsue tion at one of the shell openings and thereby drawing into the shellthrough another of the shell openings a quantity of molten metal intocontact with a remaining portion of said core material at the lower endof the shell so as to become fused with said core material, and thencausing said molten material to solidify.

8. The herein described method of producing metallic hydrometer floatswhere a portion of said float requires greater thickness than otherportions, which method consists in providing a readily meltable core,plating with metal that portion of the core which corresponds with theportion of the float requiring added thickness without plating theremainder of the core, then plating said core and said plating as onewith metal to form a thin metallic shell covering said core and saidfirst plating, the core being of material having a relatively lowermelting point than the metal of either said first plating or said secondplating, forming an opening through the shell, heating the whole toreduce the core material to a consistency for removal through saidopening and removing a portion of the core material through said openingbut leaving a sufficient portion adhering to the inner surface of theshell to constitute a thin lining upon the shell walls, and then addinga weight within the shell at the lower end thereof.

9. The herein described method of producing a hydrometer float having arelatively large bulbular portion and a relatively small stem-likeextension thereon, which method consists in providing a core piececorresponding with the shape desired for said float and being formed ofreadily meltable material, depositing as by electroplating upon saidcore a layer of metal suflicient to constitute a shell conforming to thecontour of said core, the metal of said shell having a relatively highermelting point than the material of the core, forming an opening throughthe shell at the lower end of the bulbular portion and a second openingthrough the shell at the upper end of the stem portion, heating thewhole to reduce the core material to a consistency for removal throughsaid opening and removing a portion of the core material through saidopening but leaving the remaining portion adhering to the inner surfaceof the shell, and then applying suction at the shell opening at theupper end of the stem portion and thereby drawing into the shell throughthe opening at the lower end of the bulbular portion a quantity ofweight forming material.

10. The herein described method of producing a hydrometer float, whichmethod consists in providing a core piece corresponding with the shapedesired for said float and formed of readily meltable material,depositing as by electro-plating upon said core a layer of metalsufilcient to constitute a shell, the material of said shell having arelatively higher melting point than the material of the core, forming aplurality of openings spaced apart through the shell, heating the wholeto reduce the core material to a consistency for removal through saidopening and removing a portion of the core material through said openingbut leaving the remaining portion adhering to the inner surface of theshell, and then operating at one of said openings to move a weight intothe lower end of the shell through another of said openings.

11. The herein described method of producing a waterproof metallic shellwhich method consists in providing a readily meltable core of the shapedesired for said shell, plating said core to form a thin metallic shellthereon, heating the whole to reduce the core material of suchconsistency as to be capable of flowing through a suitable opening ofthe shell, and removing a portion of the core material but leaving asuflicient portion thereof adhering to the inner surface of the shell toconstitute a thin lining upon the shell Walls HOWARD E. CHRISTIE. KIBBEYW. COUSE.

